From a B767 FCOM, FMC chapter ref Holding info entry.
LSK 2 LHS
Quadrant/Radial (QUAD/RADIAL)
The holding quadrant and radial are entered.
Valid entry is X/XXX, XX/XXX, or /XXX (example NE/040).
Automatically changes INBD CRS/DIR to agree.
These FMCs have been around for 20 years or so and therefore the 'quadrant' idea must also have been though I've never heard it in operational use from ATC.
Regards,
BH.